I’ve been a keen amateur astronomer for decades now, and while I’ve never taken the time to master all 88 constellations or complete a Messier marathon, I can find my way around the night sky comfortably well, and can talk visitors through a star party with the best of them. But something I’d always considered to be the province of experts was astrophotography. Back when I was learning to handle my first telescope, books spoke about the importance of grain, using black and white film of the highest ISO rating you could find, and then boosting the film’s sensitivity by “Hypo”ing it – a process involving soaking it in a gas mixture at certain pressures and temperatures for a specific time, if my memory hasn’t let me down. I remember one evening with my uncle at his home in Underberg when he unveiled his new toy: A CCD chip which he had assembled into a camera, complete with a peltier device attached to an aluminium block drilled with holes through which water was forced by an old aquarium pump. Instead of a radiator, he had a bucket… The whole was plugged into a wheezing old laptop through a serial port. As far as I could tell, it didn’t work very well. And that was another reason to not give it a try – it seemed that to do the new digital version of astrophotography, you needed to have piles of money (I was a student), know electronics (I liked it, but I wasn’t actually any good at it), and have access to an engineering workshop (I owned a single philips screwdriver and a pair of sidecutters).
So the years passed by, until one day the family decided that we needed a camera. So I bought a cheap entry-level compact digital camera. It was a lovely little unit, totally outclassed every cameraphone I’d ever used, and inevitably got me wondering about pointing it at the stars. I made a few attempts to capture Jupiter’s moons, Venus, even just the Moon, and all the results were blurry crap. I had figured that since it could take exposures of up to thirty seconds duration, it would be able to take some basic images. However, it turns out that you cannot hold a camera steady for that long, even if you try to brace it up against a window-frame, as I did. The solution was clearly to buy a tripod.
It was at around this time that I attended an astrophotography workshop (led by one Dale Liebenberg) at the 2012 symposium of the Astronomical Society of South Africa. Dale spoke in great detail of the processes involved in modern astrophotography – of dark frames and light frames, recording bias images and flat fields, of the relative benefits of DSLR cameras, and dedicated CCD cameras, of the light curves of different filters, and the joys of narrowband imagery. He spoke of stacking, registration, and then spent almost the entire second half of the workshop showing us how to take the completed image and bring it to life in photoshop, restoring (or inserting) glorious colours, sharpening, correcting, removing stars, or simply making them round. It was magical to watch the process, and I knew I had to do it myself.
A few months later, I’d convinced the family we needed a DSLR camera. I had no telescope, but that was merely an inconvenience – I was still busy working the mirror of the telescope that I was sure would be completed only a few months later (It’s now more than a year later. The mirror is still not completely polished…)
In that time, I’ve acquired a telescope (Celestron C8, on an equatorial wedge because it is not a goto model), T-rings and piggyback mounts to attach it to the camera, and an awful lot of frustration. It is currently Summer, which means a lot of clouds and rain. I’ve got hundreds of gigabytes of raw images, and partially processed stacks, which are frankly no good at all. The best images I’ve managed to produce came from the camera on its own tripod with the stock lens, and no telescopes at all. And while I’ve learned a lot, the most important lesson so far is: This is really hard!
I’ve not given up, though. Every night, I irritate my wife by staring out the window, waiting and praying for a clear moonless night so I can spend a few hours filling up the memory card with images that might, maybe, be a little better than what I’d recorded before. Wish me luck, and if you have any advice, please leave a comment below!